This is an example of an early Colt AR15/SP1 rifle manufactured circa 1973 that has been converted into a fully automatic class III/NFA assault rifle by the Central Kentucky Arms Company in Cynthiana, Ky. The lower receiver was remachined for the automatic sear trip and the left side has been remarked with the "AUTO" markings below the cross-pin. Currently, it is fitted with a M16A1 type upper receiver with the tear-drop forward assist and two position, flip rear sight. It is fitted with a early SP1 style standard weight, chrome lined barrel that is marked on the underside "C MP C", which is fitted with a bird-cage flash hider, standard front sight base and post sight with no other markings or proofs. It has a Colt commercial SP1 type bolt carrier with the small filler plate on the underside of the carrier (which allows it to function as a FA weapon). It has the early triangular style handguards with the early black plastic buttstock and pistol grip. This early AR15/SP1 comes with three 20 round magazines.